Hollow charge construction

ABSTRACT

A hollow charge construction in the form of a missile includes a symmetrical explosive charge having a conical forward liner and a rear spherical recess carrying an inert insert made of a material such as silicon rubber and providing guidance of the detonation waves. A detonator is arranged in the axis of rotation of the explosive charge cavity and the conical hollow charge liner and the inert insert which is arranged in the conical cavity. The explosive charge is enclosed by an aerodynamically designed cylindrical housing with a double hood portion. The detonating device is actuated by contact between the outer and inner hood walls and by transmission of a detonating pulse through an electric line which traverses the hollow charge in a longitudinal direction. The detonator in a form of a compressed charge is held centrally within a rear closing cover of the housing. The inert insert is made up of many parts having intersecting surfaces which extend at right angles to the axis of rotation of the charge.

United States Patent Thomanek et a1.

[ May 9, 1972 HOLLOW CHARGE CONSTRUCTION lnventors: Franz R. Thomanek, Sandizell; Georg Lallinger, Muhlried; Hermann Rosner, Meitingen, all of Germany Messersehmitt-Bolkow-Blohm Gesellschaft mit beschrankter Haflung, Munich. Germany Filed: June 16, 1969 Appl. No.: 833,558

Assignee:

Int. Cl. Field of Search ...l02/56, 102/24 ..F42b 13/10 102/24 HC, 56, 70.2 GA

References Cited UNITED STATES PATENTS FOREIGN PATENTS OR APPLICATIONS 81,055 6/1963 France ..102/56 568,633 7/1958 Belgium 102/56 970,395 9/1964 Great Britain. 102/24 HC 1,220,306 6/ 1966 Germany 102/24 HC Primary Examiner-Verlin R. Pendegrass Attorney-McGlew and Toren ABSTRACT A hollow charge construction in the form of a missile includes a symmetrical explosive charge having a conical forward liner and a rear spherical'recess carrying an inert insert made of a material such as silicon rubber and providing guidance of the detonation waves. A detonator is arranged in the axis of rotation of the explosive charge cavity and the conical hollow charge liner and the inert insert which is arranged in the conical cavity. The explosive charge is enclosed by an aerodynamically designed cylindrical housing with a double hood portion The detonating device is actuated by contact between the outer and inner hood walls and by transmission of a detonating pulse through an electric line which traverses the hollow charge in a longitudinal direction The detonator in a form of a compressed charge is held centrally within a rear closing cover of the housing. The inert insert is made up of many parts having intersecting surfaces which extend at right angles to the axis of rotation of the charge.

PATENTEDMY 9 1972 INVENTORS I l 7 n VQ A .H i

gn Hm mi mw GG R H z m n G r F HOLLOW CHARGE CONSTRUCTION SUMMARY OF THE INVENTION This invention relates in general to the construction of an explosive charge and in particular, to a new and useful axially symmetrically formed charge which includes an insert of inert material for the guidance of the detonation waves made of many parts having separating surfaces which extend at right angles to the axis of rotation.

The present invention is particularly concerned with a hollow charge of a type having an aerodynamic hood or cover which is formed of a plurality of wall elements which contact each other upon impact and transmit a detonating pulse to a detonator through wires which extend longitudinally through the hollow charge. The detonating cap is supported in a compressed charge which is held centrally in the rear cover of the housing.

Hollow charge designed as missiles can meet the requirements therefore better, if they are of short compact design and are characterized by a relatively low weight. Several constructional arrangements have been attempted in order to achieve these features. Thus, for example, the relatively compact design can be enhanced by the form of the aperture angle of the charging lining. If it is selected with a 60 angle or more, the overall length of the missile can be reduced since the norm is at a 42 angle. In connection with the other constructional measures it has been suggested to vary the aperture angle of the cavity (lining angle).

The effect produced by hollow charge is satisfactory where there is an obtuse angle of the lining cone and when the charge is to be used for long distances. But it drops for shorter target distances at an increasing rate in accordance with an increase the angle of the lining cone. The obtuse angle can therefore not be increased at random but there is a limit which is given in view of the requirement for maintaining the penetration of the explosive charge particularly for targets in hood distance. Depending on the intended use an aperture angle of 90 can be considered as the upper limit.

The compact design with a relatively low weight of hollow charge which is designed as a missile has been achieved for example, by the arrangement of the known inert insert for guiding the detonation waves. Such a measure, however, permits only a limited shortening of the overall length and this, in some cases, is insufficient but cannot be extended far enough so that the requirements regarding the position of the center of gravity of the device are also met. It is known to make the inert body hemispherical in the direction of flight of the hollow explosive charge and to draw it out at the rear toward the detonating device in the form of a conical tip. In each case, however, the thickness of the inert body from the apex of the cone to the front termination of the half spherical form must be great enough so that a penetration of the pressure wave through the detonation wave before reaching the axis point of the cone is impossible. The damping effect of the inert body must not drop below a certain value, that is, its longitudinal extension cannot be reduced at random if the satisfactory design of the oblong prong and thus the optimum penetration of the hollow charge is to be maintained.

An object of the present invention is to shorten the gravity position of the missile of the above mentioned type further by reducing the overall length of the hollow explosive charge despite the presently existing limits and to provide measures for its economic production. A solution of this problem is provided by arranging an inert insert of multi-part form within a conical rearwardly extending symmetrically placed recess of the hollow charge. The separating surfaces of the multi-part inert insert extend in a right angle to the axis of rotation. In a preferred embodiment, the insert comprises a ball shaped core portion having a spherical form pointing forwardly toward the vortex of the hollow charge lining. The inert insert includes a conical separate part arranged with its separating surface extending normal to the axis of rotation. The apex of the conical portion points to the apex of the hollow charge liner. Since the affect of hollow explosive charge is influenced by a great number of factors, and a variation of one of these factors influences an unknown number of other variables, it cannot be predicted with certainty what effect variation of one of these factors will have. In the present case, therefore, reliance is made primarily on observations and empirical values which could only be compiled on the basis of a long series of tests. These tests proved among other things that a reduction of the overall length of the missiles with a hollow and explosive charge is possible by the application of the concept of the present invention without loss of action. In the further development of the invention, it has been suggested that the inert parts forming the insert in the trailing end of the hollow charge liner be of the same material, for example a silicon rubber or any other material having the same explosive effect. Between the surfaces of the parts of the inert material insert which face each other or which oppose each other, there are provided spacers which prevent the tight bearing of these surfaces on one another. It is of advantage if these spacers are cut out from the full material of the opposing surfaces and have the form, for example of a concentric elevated ring.

A hollow charge and the undisturbed oblong design of its prong can be considerably impaired in its effect by axial symmetries, tolerances and manufacturing inaccuracies. Measures have therefore been taken to ensure that the path lengths between the initiation point and the limitation of the inert insert are of equal length everywhere, and that a trouble-free transmission of the detonation between the ignition point and the various explosives is insured.

In accordance with the invention, it is assured that the parts of the insert bear tightly in a recess of the explosive charge. In addition the insert includes a separate part which is conically formed and is centered in respect to the central point of a detonator held in the cover for the device. The detonator is a compressed explosive charge having a low detonation velocity. With the inventive arrangement the reliability of the hollow explosive charge in the form of a missile is increased by the constructional arrangements of the insert and the detonator. In addition, the production is simplified and reduced in cost. In accordance with a further feature of the invention the electrical detonation wires extend from the double walled hood portion through the hollow explosive charge and are embedded in the explosive thereof. The wires are conducted through tubes which are embedded in the explosive and can be closed during its casting and processing. An annular slot for the filling in of a cement is provided between the concentric receiving bore in the housing cover and the compressed charge containing the detonating cap. In order to fix and seal the housing cover a threaded ring is threaded into the end of the explosive charge housing over a deformable Teflon spacer to provide a tight fit. The housing cover also includes bores to accommodate sealing materials which may be poured in liquid form and after hardening prevent accidental displacements of the parts of the explosive charge assembly.

Accordingly, it is an object of the invention to provide an improved explosive charge construction in the form of a missile which includes a double walled hood portion which provides ignition of the explosive charge by contact between the walls and transmission through an electrical conductor extending through the charge to a detonator in the cover, and further including a recess defined in the hollow charge having a hemispherical portion pointing toward the center of the charge liner and a separate portion having a conical surface pointing toward the detonator, the two portions having a separation line which extends normal to the axis of rotation of the missile.

A further object of the invention is to provide an improved missile construction which includes a hollow charge having a conical liner extending inwardly from the forward end thereof and a rear hemispherical recess accommodating inserts of multi-part construction, the forward end of the hollow charge being closed by a double hood construction which includes walls which come together in contact upon impact and transmit an electrical ignition pulse through a connecting wire ex tending through the charge to the rear cover ofthe missile.

A further object of the invention is to provide an explosive charge construction which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing:

The only FIGURE of the drawing is an axial sectional view of the war head of a missile constructed in accordance with the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, in particular, the invention embodied therein comprises a rocket propelled missile generally designated 50 which includes a forward double walled portion comprising an outer shell 1 and an inner shell 2 which carry respective terminals 3 and 4 of an ignition circuit for the detonation of the explosive charge. A distance ring or spacer 5 is clamped between the hood shells l and 2 and prevents premature or accidental contact of the two shells. Detonation can only be initiated upon impact at the target and the deformation of the outer hood shell portion 1 as a result of a heavy blow to cause it to move into contact with the inner shell 2.

The two part contact hood portion comprising the shells 1 and 2 are secured at their inner ends to an insert ring 6 which has a thickness corresponding to the spacing between the two shells. An opposite edge of the ring 6 carries an envelope or cover portion 7 of a hollow explosive charge 8. The hollow explosive charge comprises an explosive charge portion 8 and a lining 9 of conical configuration having its apex centered and pointing rearwardly.

In accordance with the invention, the hollow explosive charge 8 is provided with a recess 10 of hemispherical form into which is positioned an inert insert ofa material such as sil icon rubber. The insert comprises a portion 11 having a hemispherical forward end which is oriented in the hemispherical recess so that its apex is centered in respect to the apex of the liner 9.

The insert comprises a plurality of parts and in this instance the forward part 11 and a trailing part 12 which is of conical configuration and which is separated from the forward part 11 by a separation line which extends normal to the axis of rotation of the missile.

A so-called point transmitter or blasting charge 13 is arranged in the rear portion of the recess 10 around the conical portion of the inert insert 12 and it terminates at a point 14 which is arranged on the axis of rotation and which is surrounded by a compressed charge or detonator 15. The compressed charge 15 is contained within a central cavity of a housing cover 17 which is secured within the end of the envelope or housing 7, which surrounds the charge 8. An annular slot 17 remaining between the housing cover 16 and the compressed charge 15 is sealed with a suitable grout or cement in order to ensure that the cover 16 and the housing 7 are rigidly connected with each other. There is a tight bearing between the explosive charge 8 and the inert insert parts 11 and 12 and the point transmitter 13. A small gap is provided between the inert insert parts 11 and 12 and a spacer 18 is provided between these parts to ensure that they do not bear tightly against one another. The spacers 18 have for example the form of concentric rings which are cut away from the full material of the core piece 11.

The threaded ring 19 is screwed into the trailing end of the housing 7 and provides a lock for the housing cover 16. A deformable plastic ring 20 is interposed between the threaded ring 19 and the housing cover 16 and it is made of a material such as Teflon to ensure complete sealing and tight fitting without turning of these two parts.

Terminals or plug pins 21 and 22 are mounted in the cover 16 and they are connected to respective ignition wires which extend through a tube 23 arranged in the explosive charge 8 and to the respective terminals 3 and 4. The tubes 23 which accommodate the respective ignition wires (only one being shown) are made of copper or any suitable material and can be laid so that the wires which are secured to the respective conductive terminals 3 and 4 of the contact hood can be safely guided. This prevents the finely stretched wires from swinging and breaking, for example, during the shipment of the war heads. The tubes 23 are conducted through the lining 9 and extend through substantially the entire length of the explosive charge 8. They terminate a few millimeters short of the end of the explosive charge 8. Before casting the explosive charge 8 the end openings of the tubes must be sealed tightly so that no liquid explosive can get to the tubes. After the explosive charge 8 has been processed the residual layer of the grout is pierced by a wire which must be introduced into the tubes. Then the electric lines can be conducted through the tube and connected with the terminals associated with the plug pins 21 and 22.

Detonation is started after the ignition circuit has been closed by deformation of the contact hood shell parts 2 and 3 so that they move into contact with each other. The detonation initiates in the compressed charge 15 with a relatively low detonation velocity. The resultant detonation wave strikes against the point 14 of the point transmitter 13 which comprises an explosive of higher detonation velocity. In this way an exactly axially symmetrical spherical wave is started in the fastener point transmitter 13 which is kept in motion by the act of damming of the compressed charge 15 since it does not lose any energy to its environment. The point transmitter 13 is arranged eccentrically in the conical seat 15 of the explosive charge 8 in order to avoid the regular transfer resistances between the compressed charge 18 and the bursting charge or explosive charge 8.

The housing cover 16 carries bores 26 for the introduction of pourable materials which are admitted and hardened therein and prevent displacement of the parts of the charge 8. The housing 7 is constructed in a curve up to the end of the detonator and it is provided with a number of fastening devices which are not shown in the drawings. It carries a casing 24 which is provided with the usual missile elements such as detonator control and propulsion units (not shown).

What is claimed is:

l. A hollow charge ofaxially symmetrical configuration particularly for use as a missile which is adapted to have detonation waves guided by an inert insert in the explosive, comprising a hollow explosive charge having a forward end with a linear and an opposite end with a cavity, an inert insert having a plurality of parts in said cavity, said parts of said inert insert having intersecting surfaces which extend at right angles to the axis of rotation of said charge, an aerodynamically shaped hood enclosing the forward end of said liner and being of double wall construction, a detonation ignition circuit including terminals in respective walls of said hood energizable by contact of said walls by deformation thereof upon impact at the target and including electrical conductors extending through said hollow charge, cover means enclosing the rear of said charge cavity, and detonator means in said cover means and connected to said electrical conductors, said inert insert parts comprising a forward part of substantially hemispherical con figuration and a rearward part having a substantially conical configuration with an apex pointing toward and centered in respect to said detonator means.

2. A hollow charge, according to claim 1, wherein said inert insert parts are both made ofa silicon rubber.

3. A hollow charge, according to claim 1, wherein said inert insert parts are separated by spacers to prevent tight bearing of the surfaces upon one another.

4. A hollow charge, according to claim 3, wherein said spacers are cut out of the material of the opposing surfaces of 5 said parts and preferably have the form of concentric elevated rings.

5. A hollow charge, according to claim 1, including an electrical conduit tube embedded in said explosive charge and extending in a longitudinal direction therein, said ignition circuit including an electrical conductor extending through said tube.

6. A hollow charge, according to claim 1, wherein said cover means comprises a cover having a central opening receiving said detonator means, said detonator means comprising a compressed charge, and cement holding said charge centrally within said cover.

7. A hollow charge, according to claim 6, including a housing for said explosive charge, said cover being threaded into the rear end of said housing, and a deformable ring arranged over said cover, and a lock ring threaded onto said housing and bearing against said ring.

8. A hollow charge, according to claim 7, wherein said cover is provided with a plurality of bores for the introduction of pourable and hardenable materials to lock the charged material in position in relation to said cover and said detonator means.

9. A hollow charge of axially symmetrical configuration particularly for use as a missile which is adapted to have detonation waves guided by an inert insert in the explosive, comprising a hollow explosive charge having a forward end with a liner and an opposite end with a cavity, an inert insert having a plurality of parts in said cavity, said parts of said insert having intersecting surfaces which extend at right angles to the axis of rotation of said charge, an aerodynamically shaped hood enclosing the forward end of said linear and being of double wall construction, a detonation ignition circuit including terminals in respective walls of said hood energizable by contact of said walls by deformation thereof upon impact at the target and including electrical conductors extending through said hollow charge, cover means enclosing the rear of said charge cavity, and detonator means in said cover means and connected to said electrical conductors, said inert insert parts including a hemispherical part bearing tightly in said cavity and a second inert insert part of conical configuration extending with its apex rearwardly and centered in respect to said detonator means, said detonator means comprising a compressed charge carried in said cover means, and a blasting charge interposed between said inert insert part and said detonator means having a point extending into said detonator.

t '8 i l 

1. A hollow charge of axially symmetrical configuration particularly for use as a missile which is adapted to have detonation waves guided by an inert insert in the explosive, comprising a hollow explosive charge having a forward end with a linear and an opposite end with a cavity, an inert insert having a plurality of parts in said cavity, said parts of said inert insert having intersecting surfaces which extend at right angles to the axis of rotation of said charge, an aerodynamically shaped hood enclosing the forward end of said liner and being of double wall construction, a detonation ignition circuit including terminals in respective walls of said hood energizable by contact of said walls by deformation thereof upon impact at the target and including electrical conductors extending through said hollow charge, cover means enclosing the rear of said charge cavity, and detonator means in said cover means and connected to said electrical conductors, said inert insert parts comprising a forward part of substantially hemispherical configuration and a rearward part having a substantially conical configuration with an apex pointing toward and centered in respect to said detonator means.
 2. A hollow charge, according to claim 1, wherein said inert insert parts are both made of a silicon rubber.
 3. A hollow charge, according to claim 1, wherein said inert insert parts are separated by spacers to prevent tight bearing of the surfaces upon one another.
 4. A hollow charge, according to claim 3, wherein said spacers are cut out of the material of the opposing surfaces of said parts and preferably have the form of concentric elevated rings.
 5. A hollow charge, according to claim 1, including an electrical conduit tube embedded in said explosive charge and extending in a longitudinal direction therein, said ignition circuit including an electrical conductor extending through said tube.
 6. A hollow charge, according to claim 1, wherein said cover means comprises a cover having a central opening receiving said detonator means, said detonator means comprising a compressed charge, and cement holding said charge centrally within said cover.
 7. A hollow charge, according to claim 6, including a housing for said explosive charge, said cover being threaded into the rear end of said housing, and a deformable ring arranged over said cover, and a lock ring threaded onto said housing and bearing against said ring.
 8. A hollow charge, according to claim 7, wherein said cover is provided with a plurality of bores for the introduction of pourable and hardenable materials to lock the charged material in position in relation to said cover and said detonator means.
 9. A hollow charge of axially symmetRical configuration particularly for use as a missile which is adapted to have detonation waves guided by an inert insert in the explosive, comprising a hollow explosive charge having a forward end with a liner and an opposite end with a cavity, an inert insert having a plurality of parts in said cavity, said parts of said insert having intersecting surfaces which extend at right angles to the axis of rotation of said charge, an aerodynamically shaped hood enclosing the forward end of said linear and being of double wall construction, a detonation ignition circuit including terminals in respective walls of said hood energizable by contact of said walls by deformation thereof upon impact at the target and including electrical conductors extending through said hollow charge, cover means enclosing the rear of said charge cavity, and detonator means in said cover means and connected to said electrical conductors, said inert insert parts including a hemispherical part bearing tightly in said cavity and a second inert insert part of conical configuration extending with its apex rearwardly and centered in respect to said detonator means, said detonator means comprising a compressed charge carried in said cover means, and a blasting charge interposed between said inert insert part and said detonator means having a point extending into said detonator. 